The complete list of best and worst U.S. markets for rental housing returns

In many parts of the country house prices are rising faster than rents, making it difficult to find investment opportunities that will cash flow. A new analysis by RealtyTrac takes a closer look at where median home prices and average rental rates make for good — and not so good — returns on rental properties. That rental return, by the way, for each county is the gross rental yield, calculated by taking the 2014 fair market rent for a three-bedroom home multiplied by 12 (months) and then dividing that 12-month total by the median sales price of residential properties in the county. Here's what they found: